diff --git a/modules/openapi-generator/src/main/resources/typescript-fetch/modelGeneric.mustache b/modules/openapi-generator/src/main/resources/typescript-fetch/modelGeneric.mustache
index 961aa9c2761c..5f4c379724b1 100644
--- a/modules/openapi-generator/src/main/resources/typescript-fetch/modelGeneric.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-fetch/modelGeneric.mustache
@@ -145,7 +145,7 @@ export function {{classname}}ToJSON(json: any): {{classname}} {
     return {{classname}}ToJSONTyped(json, false);
 }
 
-export function {{classname}}ToJSONTyped(value?: {{#hasReadOnly}}Omit<{{classname}}, {{#readOnlyVars}}'{{baseName}}'{{^-last}}|{{/-last}}{{/readOnlyVars}}>{{/hasReadOnly}}{{^hasReadOnly}}{{classname}}{{/hasReadOnly}} | null, ignoreDiscriminator: boolean = false): any {
+export function {{classname}}ToJSONTyped(value?: {{#hasReadOnly}}Omit<{{classname}}, {{#readOnlyVars}}'{{name}}'{{^-last}}|{{/-last}}{{/readOnlyVars}}>{{/hasReadOnly}}{{^hasReadOnly}}{{classname}}{{/hasReadOnly}} | null, ignoreDiscriminator: boolean = false): any {
     {{#hasVars}}
     if (value == null) {
         return value;
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchClientCodegenTest.java
index 8cdc317434da..a32753a89c20 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchClientCodegenTest.java
@@ -667,6 +667,19 @@ public void testOptionalNullableFieldDeserializesToNull() throws Exception {
         TestUtils.assertFileNotContains(modelPath, "json['required_property'] === undefined ? undefined : json['required_property'] === null ? null :");
     }
 
+    @Test(description = "Verify Omit uses the camelCase property name instead of the baseName for readOnly fields")
+    public void testIssue23380_OmitUsesCorrectPropertyName() throws Exception {
+        File output = generate(
+            Collections.emptyMap(),
+            "src/test/resources/3_0/typescript-fetch/issue_23380.yaml"
+        );
+
+        Path modelPath = Paths.get(output + "/models/Mission.ts");
+        TestUtils.assertFileExists(modelPath);
+        // Ensure Omit uses camelCase names like 'singleCar' and 'taskName' instead of snake_case 'single_car' and 'TaskName'
+        TestUtils.assertFileContains(modelPath, "export function MissionToJSONTyped(value?: Omit<Mission, 'id'|'taskName'|'singleCar'> | null, ignoreDiscriminator: boolean = false): any {");
+    }
+
     private static File generate(
         Map<String, Object> properties
     ) throws IOException {
diff --git a/modules/openapi-generator/src/test/resources/3_0/typescript-fetch/issue_23380.yaml b/modules/openapi-generator/src/test/resources/3_0/typescript-fetch/issue_23380.yaml
new file mode 100644
index 000000000000..e15cb0ff847e
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/typescript-fetch/issue_23380.yaml
@@ -0,0 +1,37 @@
+openapi: 3.0.0
+info:
+  title: Test API
+  version: 1.0.0
+paths:
+  /missions:
+    post:
+      operationId: createMission
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                mission:
+                  $ref: '#/components/schemas/Mission'
+              required:
+                - mission
+      responses:
+        '200':
+          description: OK
+components:
+  schemas:
+    Mission:
+      type: object
+      properties:
+        id:
+          type: string
+          readOnly: true
+        name:
+          type: string
+        TaskName:
+          type: string
+          readOnly: true
+        single_car:
+          type: object
+          readOnly: true
diff --git a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/Name.ts b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/Name.ts
index b999bdccb1d0..98a66b7c6a7b 100644
--- a/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/Name.ts
+++ b/samples/client/petstore/typescript-fetch/builds/default-v3.0/models/Name.ts
@@ -74,7 +74,7 @@ export function NameToJSON(json: any): Name {
     return NameToJSONTyped(json, false);
 }
 
-export function NameToJSONTyped(value?: Omit<Name, 'snake_case'|'123Number'> | null, ignoreDiscriminator: boolean = false): any {
+export function NameToJSONTyped(value?: Omit<Name, 'snakeCase'|'_123number'> | null, ignoreDiscriminator: boolean = false): any {
     if (value == null) {
         return value;
     }
diff --git a/samples/client/petstore/typescript-fetch/builds/kebab-case/models/name.ts b/samples/client/petstore/typescript-fetch/builds/kebab-case/models/name.ts
index b999bdccb1d0..98a66b7c6a7b 100644
--- a/samples/client/petstore/typescript-fetch/builds/kebab-case/models/name.ts
+++ b/samples/client/petstore/typescript-fetch/builds/kebab-case/models/name.ts
@@ -74,7 +74,7 @@ export function NameToJSON(json: any): Name {
     return NameToJSONTyped(json, false);
 }
 
-export function NameToJSONTyped(value?: Omit<Name, 'snake_case'|'123Number'> | null, ignoreDiscriminator: boolean = false): any {
+export function NameToJSONTyped(value?: Omit<Name, 'snakeCase'|'_123number'> | null, ignoreDiscriminator: boolean = false): any {
     if (value == null) {
         return value;
     }
diff --git a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/Name.ts b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/Name.ts
index b999bdccb1d0..98a66b7c6a7b 100644
--- a/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/Name.ts
+++ b/samples/client/petstore/typescript-fetch/builds/snakecase-discriminator/models/Name.ts
@@ -74,7 +74,7 @@ export function NameToJSON(json: any): Name {
     return NameToJSONTyped(json, false);
 }
 
-export function NameToJSONTyped(value?: Omit<Name, 'snake_case'|'123Number'> | null, ignoreDiscriminator: boolean = false): any {
+export function NameToJSONTyped(value?: Omit<Name, 'snakeCase'|'_123number'> | null, ignoreDiscriminator: boolean = false): any {
     if (value == null) {
         return value;
     }